Revenue bonds issued under the provisions of this act shall mature not later than 40 years after the date of issuance. Such bonds shall bear interest at a rate not to exceed the maximum rate of interest prescribed by Kan. Stat. Ann. § 10-1009, and amendments thereto. In no case where revenue bonds are issued pursuant to this act, after the project has been completed, shall the total amount received therefrom be in excess of the actual costs of the project. In the case where the bonds are issued prior to completion of the project and the total amount received therefrom exceeds the actual costs of the project when completed, then the excess shall forthwith be deposited in a separate fund and shall not be used except for the purpose of paying the principal of and the interest upon the revenue bonds issued under the act. No board or municipality shall have any right or authority to levy taxes to pay any of the principal of or interest on any such bond or any judgment against the issuing board or municipality on account thereof, and the provisions of Kan. Stat. Ann. § 10-113, and amendments thereto, shall not apply to any bonds issued hereunder.